Teenage girls who are overweight or obese are significantly more likely to develop acne than their normal-weight peers, a new Norwegian survey suggests.

Researchers looked at whether weight, and more specifically body mass index (BMI, a ratio of weight to height), had any bearing on the onset of the common skin condition among teens.

Teens' responses to questionnaires focusing on acne history and weight suggested an association among girls but not boys.

Researchers found overall, roughly 13 percent of all the girls were found to have acne. When looking solely at girls who were overweight or obese, however, this figure rose to almost 19 percent. The story was different among boys, with between 13 percent and 14 percent having acne regardless of their weight.

The reasons behind the link aren't clear, one expert said.

Overweight girls "may perceive their acne as being worse than it actually is, possibly due to self-image issues," said Dr. Robert Kirsner, a professor and vice chairman in the department of dermatology and cutaneous surgery at the University of Miami's Miller School of Medicine.

On the other hand, biology could play a role, said Kirsner, who was not involved with the study but is familiar with its findings.

"It is possible, but not yet known, that in girls, but not boys, excessive androgens caused by obesity has a greater additive effect on acne," he said. "It may be also possible that the psychological effect of being overweight in girls is greater than boys and thus leads to a more pronounced increase in stress hormones in girls, with acne as a consequence."

Source: U.S. News & World Report
http://health.usnews.com/health-news/diet-fitness/diet/articles/2012/01/16/overweight-teen-girls-may-have-higher-acne-risk